Based on the game Space Hulk, it allows you to play as alien assault team taking on a derelict space ship.
This version is as just about as complete as it will get (trust me it's comprehensive, including a tactics section). The only thing significant not in there that I'm aware of, is making addon material which will be a separate manual. Thanks to killgore85 for putting all the effort into this.
editable versions:
Mediafire.com
4shared.com
The manual helps you if you are finding the game hard. In case theres one mission really kicking your *** mainly due to the gun jamming.
Alien Assault uses the 1st Ed jam ratio of 16%, so thats 1 in every 6 shots.
Go to credits screen and type HICKS (should hear a sound):
Assault Carbines will never jam. Vulcan Cannons will never malfunction.